Atlantic Province (Acado-Baltic Province, European Province) A subdivision of the early Cambrian olenellid trilobite fauna. The trilobite faunas of the early Cambrian can be divided into two main regional groups: the olenellid fauna found in north-western Europe and N. America, and the redlichiids in Asia, Australia, and N. Africa. The olenellid fauna is also subdivided into two provinces: the Atlantic Province on the southern and eastern flank of the Iapetus Ocean, and the Pacific Province or (American Province) on the northern and western margins. The names Atlantic Province and Pacific Province have also been applied to the Ordovician trilobite and graptolite faunas in the same areas.

Atlantic North American floral region Part of R. Good's (1974, The Geography of the Flowering Plants) boreal kingdom. It is a large and extensive flora with 100–200 endemic (see endemism) genera. Robinia (false acacia) is a well-known example, and there is also Franklinia, a garden tree (not hardy in Britain) that was obtained from a single plant of a single species, and which is now extinct in the wild. As a whole the flora strongly resembles those of temperate Eurasia, China, and Japan. See also floral province and floristic region.

Atlantic North American floral region Part of R. Good's (The Geography of the Flowering Plants, 1974) boreal kingdom. It is a large and extensive flora with 100–200 endemic (see ENDEMISM) genera. Robinia (locust tree) is a well-known example, and there is also Franklinia, a garden tree that was obtained from a single plant of a single species, and which is now extinct in the wild. As a whole the flora strongly resembles those of temperate Eurasia, and of China and Japan. See also FLORAL PROVINCE and FLORISTIC REGION.